This invention relates to attachments used with a retractable tape measure to draw circles, arcs, and intersecting arcs and is an improvement over the device disclosed in my prior application, Ser. No. 08/944,722, now abandoned and incorporated by reference.
Acknowledging the technical field, sheet metal technicians, pipe fitters, and steel fabricators often rely on arc forming devices to draw circles, arcs, and intersecting arcs for developing full scale patterns common to their trades.
Since retractable tape measures are widely used in these operations, it is often convenient efficiency to fasten a marking instrument to a tape measure housing containing a retractable scale having a tab affixed to the zero end thereof the scale, wherein the tab is fastened to a pivotal means permitting the user to rotate the tape measure housing and marking instrument about an axis defined on the surface underlying the tape measure. With the marking instrument engaging the surface, the user can draw circles, arcs, and intersecting arcs for developing patterns thereon the surface underlying the tape measure.
Although prior inventions include a number of fixtures and attachments to be used with retractable tape measures to draw circles and arcs, it is believed the devices are not widely available because of manufacturing difficulties and the manner in which the devices operate.
Accordingly, it is an object of the present invention to provide a more efficient tool for drawing circles, arcs, and intersecting arcs for developing patterns on ferrous or non surfaces, wherein the pattern developing tool comprises an axial pivotal bracket, and marker holder used with a retractable tape measure having a tab affixed to the zero end thereof a measured scale retractively coiled within a housing disposing a belt clip and means for locking the scale at predetermined measurements, said pattern developing tool providing improved means for fastening a marking instrument to said housing and improved means for pivoting said housing and marking instrument about an axis defined on a ferrous or non ferrous surface underlying said tape measure, permitting the user to draw accurate circles, arcs, and intersecting arcs for developing patterns thereon said surfaces.
It is another object of the present invention to provide a pattern developing tool wherein said fastener means consists of a marker holder adapted to recieve and hold a flat soapstone or other preferred marking instrument, said marker holder disposing first and second channels, wherein said first channel cooperates with said tape measure belt clip to facilitate effective connection of said marker holder thereto said housing, said second channel cooperates with said tape measure scale and housing facilitating coplanar alignment of said marker holder therewith said scale and perpendicular alignment of said marking instrument therewith said underlying surface.
It is another object of the present invention to provide a pattern developing tool wherein said pivotal means consists of a pivotal bracket disposing a first aperture therein cooperating with opposed side walls to facilitate simultaneous connection and coplanar alignment of said pivotal bracket thereat said tab and scale, said pivotal bracket disposing a second aperture therein for recieving said axial pilot, wherein said axial pilot is affixable to ferrous or non ferrous surfaces underlying said tape measure, permitting the user to rotate said tape measure housing about an axis defined on said surfaces, whereby a marking instrument can be fastened to said marker holder connectable to said housing, permitting the user to draw accurate circles, arcs, and intersecting arcs for developing patterns thereon said surfaces.